Botulism

Audience This simulation is targeted to emergency medicine residents and medical students. This case focuses on the diagnosis and management of botulism toxicity, while highlighting the logistical complications of botulism toxicity. Introduction Botulism is a potentially life-threatening emergency that often presents with subtle symptoms, which can progress to paralysis and respiratory failure. A descending flaccid paralysis is typical, initially affecting smaller muscles such as oculomotor, then larger facial muscles. 1,2 Early indications of respiratory compromise are important to recognize. It is important for emergency medicine physicians to be familiar with botulism and recognize the presentation quickly to safely treat the patient. Clinical findings may include: dilated pupils, diplopia, xerostomia, dysphagia, and nausea and vomiting. 3 Treatment priorities include assessment and management of the airway, close monitoring, and coordinating with local agencies to obtain botulinum antitoxin.1 Educational Objectives By the end of this simulation learners will be able to: 1) develop a differential for descending paralysis and recognize the signs and symptoms of botulism; 2) understand the importance of consulting public health authorities to obtain botulinum antitoxin in a timely fashion; 3) recognize that botulism will progress during the time period antitoxin is obtained. Early indications of respiratory compromise are expected to worsen during this time window. Secondary learning objectives include: 4) employ advanced evaluation for neurogenic respiratory failure such as physical examination, negative inspiratory force (NIF), forced vital capacity (FVC), and partial pressure of carbon dioxide (pCO2), 5) discuss and review the pathophysiology of botulism, 6) discuss the epidemiology of botulism. Educational Methods This simulation was conducted using a high-fidelity mannequin with intubating capabilities and real-time vital sign monitoring. Following the simulation, the participants underwent a debriefing session and discussion on botulism. This case was designed as a high-fidelity simulation, but it can be adapted to a low-fidelity simulation or case discussion. Research Methods Following the simulation and debriefing session, participants were provided with a survey to rate the simulation and provide feedback to instructors. Participants were asked open-ended questions about the strengths and areas of improvement of the case, and were asked to rate how they valued the learning content of the case on a 5-point scale. Results Emergency medicine residents expressed positive feedback on the scenario. The residents appreciated the change in clinical course of the patient over time as well as the presentation of botulism. Discussion This simulation is an effective way of teaching about botulism to emergency medicine residents. We used a primary nurse asking questions to progress the case and stimulate the learners to think about certain specific aspects of the case, such as the patient’s weakness or disposition. Topics Toxicology, botulism, emergency medicine, medical simulation.


Linked objectives and methods:
Botulism is an uncommon emergency department (ED) presentation with subtle nonspecific symptoms. Other diagnoses that could be considered include but are not limited to: tick paralysis, myasthenia gravis, cerebrovascular accident, multiple sclerosis, malignancy, and ciguatera toxicity. This scenario emphasizes the importance of maintaining a high clinical suspicion for botulism in at risk populations, which can be ascertained from thorough history gathering (objective 1). Learners will need to identify early signs of respiratory failure through thorough examination and ancillary testing (objective 4). Once diagnosed, learners will need to facilitate obtaining the antitoxin and consult the appropriate services/agencies (objective 2). While waiting for the antitoxin to arrive, learners will need to reassess the patient and continue to monitor their respiratory status and disposition appropriately (objective 3). Following the simulation there will be a debriefing and discussion on the etiology, epidemiology, and pathophysiology of botulism (objectives 5,6). This simulation will reinforce the prompt evaluation, diagnosis, management, and reassessment necessary to appropriately treat botulism (objectives 1-6) in a safe learning environment, and participants will receive feedback on their performance.

Recommended pre-reading for instructor:
If the instructor is not familiar with botulism, we recommend any of our textbooks referenced in the references section, such as Goldfrank's Toxicologic Emergencies. Reviewing the local policies (if in place) in their hospital for obtaining antitoxin may be beneficial to customize the simulation to the local environment of the learners.

Results and tips for successful implementation:
This simulation was designed for emergency medicine residents on a toxicology rotation. It was performed in a high-fidelity simulation setting; however, it can be adapted to be an oral case discussion or performed in a low-fidelity scenario. This case was designed and implemented during the 2019-2020 academic year. The case was piloted with 12 learners over three sessions spaced one month apart each. All learners were from the same institution, and there are typically 3-4 learners per month. Learners were queried in person and via anonymized online survey about the strengths and potential improvements of the case. All respondents indicated 5 out of 5 (maximal agreement) to the following three statements: • This experience will improve my performance in actual clinic setting. • This simulation was a valuable learning experience.
• The debriefing was a valuable learning experience.
Thematic analysis of the two open-ended questions "How could this experience be improved?" and "What were the strengths of this experience?" were universally positive. Specifically, learners appreciated the differential diagnosis, diagnostic approach to the rare case, the discussion of the approach to obtaining antitoxin, and how the case required a thorough physical examination and performance of a social history. Iterative improvements were made to the case (more detailed differential diagnosis, more detailed neurological examination, and addition of cueing prompts by nurse when necessary)

Objectives:
By the end of this simulation learners will be able to: 1. Develop a differential for descending paralysis and recognize the signs and symptoms of botulism. 2. Understand the importance of consulting public health authorities to obtain botulinum antitoxin in a timely fashion. 3. Recognize that botulism will progress during the time period antitoxin is obtained.
Secondary learning objectives include: 4. Employ advanced evaluation for neurogenic respiratory failure such as physical examination, negative inspiratory force (NIF), forced vital capacity (FVC), and partial pressure of carbon dioxide (pCO2). 5. Discuss and review the pathophysiology of botulism. 6. Discuss the epidemiology of botulism. To provide help during the simulation to the learners if necessary, the primary nurse would ask questions about the patient periodically to guide them to think about respiratory status and disposition. The learners appreciated the change in clinical course of the patient over time as well as the presentation of botulism. Based on anonymized surveys, learners valued a thorough differential in the debrief, the workup and management of suspected botulism, and the process to obtain the antitoxin. " He has been triaged as a low acuity patient and in the waiting room for four hours. He initially has normal vital signs; however, over the course of the simulation develops descending paralysis and respiratory failure. He will require thorough evaluation for neurogenic respiratory compromise with negative inspiratory force (NIF) and forced vital capacity (FVC) testing. Examination will reveal development of tachypnea, xerostomia, and peripheral weakness on neurological exam. Diagnostics will reveal hypoxia on room air and pending respiratory failure. He subsequently will require intubation and intensive care unit (ICU) admission. He will also require that the provider contact a public health authority such as their local poison center, state health department, or Center for Disease Control and Prevention (CDC) to arrange for delivery of botulinum antitoxin.

Background and brief information:
A 35-year-old man with a history of intravenous black tar heroin abuse presents to the Emergency Department (ED) for evaluation of dry mouth, weakness, and difficulty holding a cigarette in his mouth. He has been triaged as a low acuity patient and has been in the waiting room for four hours.
Initial presentation: This is the case of a 35-year-old man with history of daily intravenous heroin abuse who has developed wound botulism. Over the course of a few hours, he has descending paralysis which progresses to respiratory compromise and ultimately respiratory failure. The case will test the examinee's ability to diagnose botulism, obtain the antitoxin, recognize abnormal vital signs and protect the patient from lethal respiratory paralysis.

How the scenario unfolds:
1. The patient will wait in the waiting room for 4 hours prior to physician evaluation. 2. The patient will have developed rapid shallow breathing (RR 22) and mild hypoxemia (94% on RA) during his time in the waiting room. 3. Physical examination will show symmetric abnormal lower motor neuron findings without sensory findings. 4. Patient will require botulinum antitoxin, which must be acquired by contacting a public health agency. It is expected that there will be a delay of 6-12 hours until the antitoxin reaches the patient. Antitoxin halts progression of paralysis but does not reverse it. 5. Patient is expected to develop progressive respiratory paralysis over the next several hours. Based on clinical evaluation, including possibly NIF and FVC, patient should be intubated. 6. Patient should be admitted to the ICU.
Critical Actions: 1. Recognition of botulism poisoning The patient will have cranial nerve weakness with progressive descending paralysis. The differential includes but is not limited to: botulism, myasthenia gravis crisis,

Intubate the patient in the emergency department
Given the progression of respiratory weakness during the patient's ED stay and the inherent delay in antitoxin acquisition, the patient should receive intubation in the ED. The patient will not develop respiratory failure in the simulation if intubated. Without intubation he is likely to develop respiratory failure over the next several hours and will code once admitted. a. Cuing Guideline: Nurse can ask doctor how quickly botulism acts. If the team intubates the patient, he will stabilize. If the patient is not intubated, he will develop worsening respiratory function. If the patient is not pre-oxygenated prior to intubation, he will have an oxygen desaturation during the procedure.

Call public health agency to coordinate antitoxin delivery
If the team does not intubate the patient, he will require intubation after admission, or suffer a cardiac arrest if not admitted to ICU. This must be clarified during the debrief. If the team contacts a public health agency the patient will receive antitoxin within 8 hours.
If the team does not contact a public health agency the patient will not receive antitoxin and will have a prolonged illness. This must be clarified during the debrief. intubation and mechanical ventilation should be considered if there will be a significant delay until antitoxin administration. The 24/7 phone number for obtaining botulinum antitoxin from the CDC is (770) 488 -7100. This can also be coordinated by calling Poison Control at 1 -(800) 222 -1222.
Wound botulism is often related to seemingly minor wounds that do not require interventions such as antibiotics or excision. Black tar heroin use has become a leading risk for development of wound botulism. If a patient has an infected wound it should be treated and debrided.
The epidemiology of botulism is primarily based on exposure history. Exposures to botulism include: • Homemade preserved food (canned goods, "muktuk" which is traditional fermented whale blubber, "pruno" which is fermented alcohol product brewed in prison, viscous inadequately refrigerated food such as gas station cheese dip) • Honey in neonates • Black tar heroin use (more commonly seen in Western than Eastern United States) • Iatrogenic sources (cosmetic or therapeutic botulinum injections) Wrap Up: Botulinum disrupts the presynaptic SNARE proteins in the lower motor neurons. SNARE proteins are involved in release of acetylcholine vesicles. As a result, no acetylcholine can be released into the neuromuscular junction and paralysis ensues. The affected SNARE proteins are permanently disabled, and so restoration of neuron function requires synthesis of new SNARE proteins and axonal transport to the synapse. It may take weeks for neuron function to return. Botulinum antitoxin halts disease progression, but does not reverse it. For example, administering antitoxin may prevent a patient from requiring intubation if given early; however, patients treated with antitoxin will still require weeks to regain their strength and may require physical therapy, home health services, and hospital admission.

Milestone
Did not achieve level 1 Level